Hey Matt did you have to do a lot to the suspension to compete in Auto cross?
In retrospect, not really. At the time, it seemed like an endless effort.
The long winded version is on my website. But the short of it is this:
Parts
Big torsion bars. Started with 1.03, now 1.09"
Front anti-sway bar. 1.125"
200 "/lb asphalt track rear leafs with 5" free arch IIRC.
for autocross, spring hanger change so the front eye is higher than stock.
for rallycross and crappy roads, stock position.
Good shocks. Mine are SPAX but there are easier to obtain options now.
Polyurethane strut rod bushings measured and cut to fit.
That's really about it in terms of suspension parts.
I did try to stiffen the body, and I'm sure it helped a little. The frame connectors need to be replaced as they've rusted through. Current rules allow a third attachement point, so that may help.
Steering is 16:1 manual box. That's works reasonably well with some technique.
Competition tires are generally 225/50-15. Just switched to 235/50r15 Toyo R888s this year. I'd say tires, shocks and sway bar are the most important items needed.
Eventually I'm going to experiment with some softer rear leafs and a small rear sway bar.